Borehole closures are used as auxiliary means, i.a., in mining, underground mining as well as in the field of building rehabilitation for injection of, for example, turbid cement, synthetic resin, water glass or the like into the rock formation or masonry. With the assistance of these impregnating fluids, the rock formation or the masonry is intended to be consolidated. Also seals can be realized.
Within the scope of DE 42 09 802 C1, a borehole closure is known which has been proven in practice. Practice has also shown that improper handling, especially during insertion of the borehole closure in a bore, led oftentimes to a cracking of the supply line within the inflating tube, when the supply line is made of plastic. The reason for that is an circumferential inward turning of the supply line in the region of the transverse passages, which connect the longitudinal passage in the supply line with the annular chamber between the supply line and the inflating tube, for fixedly securing a sealing ring, which covers the ports of the transverse passages and reduces the cross section of the supply line. As a result, the borehole closure becomes useless.
Also EP 0 398 838 A1 shows a borehole closure of this type.
DE 24 02 509 A1 discloses a tubular one-way borehole closure for injection of synthetic resin, including a pipe piece with sleeve-like inlet and outlet parts. Secured to the inlet and outlet parts is a tube portion of elastic material with band clamps. Disposed on the outlet part is a non-return valve with a ball and an axially aligned slotted heavy type dowel pin. When the ball rests upon the opening of heavy type dowel pin, the slot in the heavy type dowel pin assumes the function of a throttle path for the injection medium. Furthermore, the central part of the pipe piece with the provided transverse passages on the circumference is not weakened by a groove.
DE 30 14 834 A1 conveys to the artisan a borehole closure with non-covered transverse passages between an annular chamber, which is formed by a rubber tube and a pipe piece, and the interior of the pipe piece. The transverse passages are provided off-center of the annular chamber extension. Further described is the installation of non-return valves on the feed end as well as also on the discharge end.
Starting from the state of the art, the invention is based on the object to provide a borehole closure which is more flexible to adapt to local conditions and which can easily be placed in appropriate position in a borehole, even when handled improperly.